Injection of liquid fuel in internal combustion engines



July 12, 1932. L. K. BRAREN INJECTION OF LIQUID FUEL IN INTERNAL COMBUSTION ENGINES H 4@ www H4 1 :L OJ 8 H m 3 m a wfw m h 6 wv 77 IMI A. E LMI@ I f July l2, 1932. 1,867,491

INJECTION oF LIQUID FUELy IN INTERNAL coNBUsTIoN ENGINES I L. K. BRAREN 'Filed Jan. 25. 192'? 2 sheets-smeet 2 Patented July 12, 1932 UNrri-:D STATES PATENT orrlcl-:f

LORENZ KONRAD BRAREN, OF MUNICH, GERMANY, A'SSIGNOR TO THE IEIBJVI:A FRIEDRICH DECKEL.PRAZISIONSMECHANIK, UND MASCHINENBAU, F MUNICH? BAVARIAQGER- INJECTION OF LIQUID' FUELIN INTERNAL COMBUSTION ENGINES Application med January 25', 1s27,seria1 No. wasmand in Germany February 4, 192e.

This invention relates to the'injection of liquid fuel into the cylinders of internal c ombustion engines of thc Diesel or seml-Dlesell type, where the fuel is injected into the combustion chamber at or about the end of the compression period and refers especially to engines using an emulsion of liquid fuel and air or another gas as described in my copending application, Serial No. 75,452,'iled Dec. 14, 1925. j

The object of my invention is to provide a method and means for regulating over a wide range the quantity of fuel injected even with 'a considerable variation of speed. This object is attained by regulating the pressure of the emulsion. The amount of fuel may further be varied by changing the duratlon `of injection, as the emulsion is-stored under pressure in a chamber and passes into the combustion chamber in an even stream. The duration of the flow of course'depends on the time during which the injection valve is held open. Furthermore the quality of emulsion may be changed whereby a certain amount of regulation is attained. These factors lalone or combined .permit an extended regulation of the fuel as is necessary for varying the speed and the load of an engine over a .wide range'.

A further object of my invention is to conduct the emulsion to the injection valve which is operated by a cam shaft or hydraulically in well known manner. Excessive emulsion passes to a pressureregulatingmechanism ,the return line which may be located in the pump or in a convenient position 'on the engine. In the flrst case I arrange the return line surrounding the fuel line. 4 j

I construct these lines large enough in order to prevent great variations in pressure or providean equalizing chamber of suliicient capacity, which is advantageously located on in order to bring always quickly fresh emulsion to the injection valve or valves as the casemay be.

The above and various other improvements will be hereinafter fully described and claimed. In order that this my invention may be more readily understood reference is made to the accompanying sheets of drawings. which show how the invention vthe plunger.

uncovers passages 46 may be carried into practical effect.

Fig. 1 is a longitudinal section through the fuel pump.

Fig. 2 is a cross section through the pump.

ig. 3 is a section substantially on the line A of Figure 1.

Fig. 4 is a section substantially ,on the line `B 'of Figure 1.-

Figx is a top view of the pump partly in sectlon. f

Figr shows the regulation of the injection valve.

Fig. 7 shows a different regulation of the injection valve and Figi 8 shows the general arrangement for a number 'of cylinders with the pressure regulatingl means arranged separate from theA fuel pump.

A crankshaftl journaled in the base 2 of the pump has two cranks 3 and 4 which drive respectively two pitmen 5 and 6 and two plungers 7 and 8 (Figure 1)-. The bores for these plungers are arranged in the pump body 9 which is fastened to the base 2. cover 10 completes the pump housing. The plunger 8 measures oft1 the liquid fuel entering through a line 11 and a passage 12 from the fuel tank not shown (Figure 2). An axially adjustable sleeve 13 regulates the quantity of fuel delivered for eachstroke of A reduced portion 14 of the plunger 8 enters more or less deeply into the -bore .of the'sleevc 13 according to the axial position of the latter and a corresponding amount of fuel is driven through the central bore 15` past a on the circumference of the plunger 8. The fuel is injected with considerable pressure through the passage 18k in the pump body 9 into the second cylinder. The axial adjustment of the sleeve 13 is attained by a gear 19 engaging witha gear rack 19a cut on the sleeve 13. The gear 19 is journaledl on a shaft 20 and may be turned by an operating member 21. Y

The plunger 7 in the lower dead' center permitting air or another gas to enter which gas is compressed on the upstroke. During the compression check valve 16 into a recess 17' ice stroke the fuel is injected into the air cylinder. The compressed fuel-gas-emulsion streams through a passage 22 in the piston 7, a hole 23 in the pump body 9, a hole 24 in the fuel piston 8 and a passage 25 in the pump body into a chamber 26 from where it 1s distributed to a number of fuel lines 27 which conduct the emulsion to the combustion chambers (Fig. 3). The transfer is timed by the passages and the relative position of the plungers thus preventing a return low of the emulsion on the downward movement of the plunger 7.

The line 27 communicates with a passage 51 in the injection valve body 52 (Fig. 6) from where the emulsion passes through groove 53 of a bushing 54 under the partially reduced end of the injection needle 55. Emulsion above the requirements of injection passes through a groove 47 on the opposite side of the bushing 54 into a second passage 56 in the valve body 52 which passage stands in communication with a circular groove 57 in a bushing 48 pressed unto the end of the valve body 52. This groove leads the emulsion to a circular recess 58 of the nipple 59 of the fuel line 27. The recess 58 communicates through several passages 60 with the interior of a second tube 28 surrounding the lfirst line 27. A nut 61 holds the flared outer end of the tube 28 against a shoulder of the nipple 59 pressing thus the latter on its conical seat. `The injecting needle 55 is held by a rod 63 and a spring 62 on its seat as long as a bushing 64 is held depressedby a sleeve 65 and a lever 66. Otherwise the bushing 64 rests against a nut 67 on the rod 63 removing thus the pressure of the spring 62 from the needle 55. The compressed emulsion then lifts the injecting needle and the fuel streams through the opening 68 into the combustion chamber. The lever 66 is controlled by a triangular depression on a cam 69 rotating in fixed relation with the engine crankshaft. The cam can 4be moved axially in order to bring a smaller or wider opening 70 underneath the cam roller causing thus a different duration of injection.

. Excessive emulsion passes from the tube 28 through passages 29 in the connection and openings 30 and 31 in the pump body into a chamber 32 provided for equalizing the pressure Figs. land 3. This chamber is not necessary in case the tubes are made large enough to give the required capacity. For regulating the height of the pressure of the emulsion there is provided a piston 34 in a bushing 34a communicating with the pressure chamber 32 and having a discharge opening 95 controlled by the piston 34 which is normally depressed by a spring 33 (Fig. 1). In a certain axial position of lthe piston, openings are uncovered which permit emulsion to pass through holes 35 and 36, passages 37 and 37a, the latter formed ed on the circumference with gear teeth similar to those at the sleeve 13. A gear 40 in engagement with the teeth on the sleeve 39 is journaled on the shaft 20. The operating means for the gear 40 is the same as that shown in Fig. 2 for operating the gear 19, the parts being the same in both cases including the operating and locking parts 41 and 45 respectively and the toothed segment 44 as well. Turning of the operating "member 41 will vary the spring pressure onthe piston 34 and therewith the pressure underwhich the emulsion is kept. e

In order to combine the regulations of the quality of the emulsion effected bv the axial position, of the sleeve 13 and the height of the pressure of the emulsion influenced by the axial position of the-sleeve 39, the gear 19 is arranged to slide axially and has teeth on one operating members at 21, each locking member having a tooth 45a movable from engagement with its toothed segment by swinging the locking member upwardly.

A modified construct-ion of the injection valve is shown in Figure 7. where the spring tension on the valve needle is removed by a projecting cam nose which construction'is of particular advantage in combination wlth a decompression valve.

The fuel lines 27 -and the return lines 28 are fastened similarly as in Figure 6 by a nut 61 and a nipple 59 to a connection 71. There are provided two separate passages 72, 73 'for the entering and 74, 75 for the returning emulsion. The valve needle is held on its seat by a bolt 77 and a spring 78. A lever 79 contacts at 79a with a protruding portion 77 n on the stein of the bolt 77. This lever is actuated by a second lever 81 by an adjusting screw 8O through a triangular projecting cam 83 on a cam shaft 82 suitably driven by the engine. The shaft 84 on which the levers 79 and 81 are journaled is mounted in upstanding lugs 84EL on a ring 85 fastened to the Valve body 86.- The valve body whichl serves at the same time as decompression valve for the combustion chamber is held normally closed by a spring 87 but can be depressed by a cam 89 operating on a lever 88 pivoted at 88a and engaging the upper end of the body. ln the depressed position of the formed I do 'return passages 47, 56, 57 or 74, 7 5,

tion is stopped. A threaded sleeve 90 surrounding the spring 78 limits jecting needle 76. or a ne adjustment of the threaded sleeve'a screw 91 is provided in engagement with a gear 91a fixed on the threaded sleeve 90. A square end 92 ofthe screw 91 can be reached conveniently by -a suitable wrench from the outside.

Figure 8 shows al general arrangement of the fuel lines With the 'pressure regulating means arranged separate from the fuel pump. The emulsion passesffrom the fuel pump 9 through the lines 27 to the cylinders. Short connecting lines 93 lead to the injection valves. The pressure regulating mechanism indicated diagrammatically at 39a in Fig. 8 is arranged at the end of the line in a position convenient for the operator. All excess emulsion passes this regulating mechanism through the return line 88 into the tank 38a.

As this return line is' not standing under a high pressure any leakage from the injection valves is conducted through the tubes 94 inte the line l38. The injection valve indicated diagrammatically in Fig. 8 may be the valve 52 of Fig. 6 or the valve 86 of Fig. 7. The injection valves in this case do not need the While the tu which the spring is contained.

Having now particularly described and ascertained the nature of this my invention and in what manner the same is to be pernot wish tb be understood as limiting myself to the exact details of construction as obviously many modifications will occur to a person skilled'in the art.

What I claim is:

1. In internal combustion engines of the type Where the fuel is injected into the combustion chamber at or near the end of the compression period, means for mixing and compressing liquid fuel and regulating the pressure under which the fuelgas-emulsion is held, and means for varying the duration o f fuel injection, both said pressure and time regulating means being adapted for varying the amount of fuel 1njected during each cycle of Voperation of the internal combustion engine.

2. In internal combustion engines of the type Where the fuel is bustion chamber at or near the end of comregulating the pressure under which the fuelgas emulsion is kept,and means for conducting the emulsion to the combustion chamber, said means being in communication with said pressure regulating means.

pression, means l type Where the fuel D compression y period,

s 94 communicate With-the chambers in b a gas, means for b of operation, an

injected into the comj means for selectively.V

3. In internal combustion engines of the type where the fuel is injected into the comustion chamber compressing liquid fuel a gas, and means for re ulathe pressure of load on said plunger, for selectively varying the elastic load on said plunger. In internal combustion enginesof the is injected into the combustlon chamber at or near the `end of the compression period, means for mixing and compressing liquid fuel and a gas, means for regulating the quality of the emulsion, differ-I ent means for regulating thepressure of the emulsion, and means for connecting both said regulating mea to be varied together.

5. In internal combustion engines of the type Where-the fuel is injected into the combustion chamber at or near. the end of the compressing liquid yfuel and a mechanism, a valve closing the fuel passage to the combustion chamber, an elastic load ony said valve for holding it normally closed, and means for removing said elastic load periodically, the duration of the periodjdetermining the amount of fuel injected.

6. In internal combustion engines of the type Where the fuel is injected into the comustion chamber at or near the end of the compressionl period, means for storing a. quantity of fuel under pressure, means for holding the pressure approximately constant during operation, an an injecting mechai nism having a valve for closing the fuel pas-v sage to the combustion chamber, an elastic load for holding said valve normally closed, means for lifting saidvalve periodically for n combustion chamber,

for varying lifting In internal combustion engines of the Where the fuel is injected into the comustion chamber at or .near the end of the compression, means for placing fuel un'der pressure, a storage for a quantity'of fuel f under pressure, means for holding the pressure approximately constant during a cycle an injection mechanism, said injecting mechanismfor freeing said valve periodically for operation by the pressure in advance of the injection of the fuel into the combustion chamer, an adjustable stop for limiting the lift of said valve and means for varying the duration of the lifting period. l K

n internal combustion engines of the type where the fuel is injected into the comooi combustion chamber, said bustion chamber at or near the end of the compression period, means for placing fuel under pressure, a storage for a quantity of fuel under pressure, means for holding the pressure approximately constant during a cycle of operation, a -pressure responsive valve for closing the fuel passage to the combustion chamber, an elastic load for holding said valve normally closed,-means for freeing said valve, means for varying the duration of the opening period, for limiting the height of the lift of said valve, and means for adjusting said stop without removing the injection mechanism from the engine. 'In internal combustion engines of the type-where the fuel'is injected at or near the end 1. of compression, a fuel pump, an inject-ion mechanism, and a decompression valvefor the combustion chamber, said injection mechanism being arranged within said decompression valve.

10. In internal combustion engines of the type Where the fuel is injected at or near the end of compression, a fuel pump, an injection mechanism, decompressing means for permitting the compressed fuel to escape under predetermined conditions from the injection mechanism located in said decompressing means, and means for interrupting the operation of said injection mechanism upon operation of said 'decompressing means. f

In testimony whereof I hereunto aix my signature.

LORENZ KONRAD BRAREN.

an adjustable stop 

